From 2ba039f945c54637fb15a6527e56f559b87b35d8 Mon Sep 17 00:00:00 2001
From: Jonathan Leitschuh <Jonathan.Leitschuh@gmail.com>
Date: Fri, 4 Nov 2022 15:08:47 +0000
Subject: [PATCH] vuln-fix: Zip Slip Vulnerability

This fixes a Zip-Slip vulnerability.

This change does one of two things. This change either

1. Inserts a guard to protect against Zip Slip.
OR
2. Replaces `dir.getCanonicalPath().startsWith(parent.getCanonicalPath())`, which is vulnerable to partial path traversal attacks, with the more secure `dir.getCanonicalFile().toPath().startsWith(parent.getCanonicalFile().toPath())`.

For number 2, consider `"/usr/outnot".startsWith("/usr/out")`.
The check is bypassed although `/outnot` is not under the `/out` directory.
It's important to understand that the terminating slash may be removed when using various `String` representations of the `File` object.
For example, on Linux, `println(new File("/var"))` will print `/var`, but `println(new File("/var", "/")` will print `/var/`;
however, `println(new File("/var", "/").getCanonicalPath())` will print `/var`.

Weakness: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Severity: High
CVSSS: 7.4
Detection: CodeQL (https://codeql.github.com/codeql-query-help/java/java-zipslip/) & OpenRewrite (https://public.moderne.io/recipes/org.openrewrite.java.security.ZipSlip)

Reported-by: Jonathan Leitschuh <Jonathan.Leitschuh@gmail.com>
Signed-off-by: Jonathan Leitschuh <Jonathan.Leitschuh@gmail.com>

Bug-tracker: https://github.com/JLLeitschuh/security-research/issues/16


Co-authored-by: Moderne <team@moderne.io>
---
 .../boot/src/main/java/org/wildfly/core/jar/boot/Main.java    | 4 ++++
 .../main/java/org/jboss/as/cli/handlers/ArchiveHandler.java   | 3 +++
 patching/src/main/java/org/jboss/as/patching/ZipUtils.java    | 2 +-
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/bootable-jar/boot/src/main/java/org/wildfly/core/jar/boot/Main.java b/bootable-jar/boot/src/main/java/org/wildfly/core/jar/boot/Main.java
index e0ae16c91e7..492aa535b41 100644
--- a/bootable-jar/boot/src/main/java/org/wildfly/core/jar/boot/Main.java
+++ b/bootable-jar/boot/src/main/java/org/wildfly/core/jar/boot/Main.java
@@ -18,6 +18,7 @@
 
 import java.io.BufferedReader;
 import java.io.File;
+import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.lang.reflect.Method;
@@ -210,6 +211,9 @@ private static void unzip(InputStream wf, Path dir) throws Exception {
             while (ze != null) {
                 String fileName = ze.getName();
                 Path newFile = dir.resolve(fileName);
+             if (!newFile.normalize().startsWith(dir.normalize())) {
+              throw new IOException("Bad zip entry");
+             }
                 if (ze.isDirectory()) {
                     Files.createDirectories(newFile);
                 } else {
diff --git a/cli/src/main/java/org/jboss/as/cli/handlers/ArchiveHandler.java b/cli/src/main/java/org/jboss/as/cli/handlers/ArchiveHandler.java
index 13c33d71b05..ba731b95ef4 100644
--- a/cli/src/main/java/org/jboss/as/cli/handlers/ArchiveHandler.java
+++ b/cli/src/main/java/org/jboss/as/cli/handlers/ArchiveHandler.java
@@ -163,6 +163,9 @@ private File extractArchive(File archive) throws IOException {
             for (Enumeration<JarEntry> entries = jarFile.entries(); entries.hasMoreElements();) {
                 JarEntry entry = entries.nextElement();
                 File file = new File(tempDir, entry.getName());
+             if (!file.toPath().normalize().startsWith(tempDir.toPath().normalize())) {
+              throw new IOException("Bad zip entry");
+             }
                 if (entry.isDirectory()) {
                     file.mkdir();
                     continue;
diff --git a/patching/src/main/java/org/jboss/as/patching/ZipUtils.java b/patching/src/main/java/org/jboss/as/patching/ZipUtils.java
index 722b00c6ce5..6ed5833caf3 100644
--- a/patching/src/main/java/org/jboss/as/patching/ZipUtils.java
+++ b/patching/src/main/java/org/jboss/as/patching/ZipUtils.java
@@ -119,7 +119,7 @@ private static void unzip(final ZipFile zip, final File patchDir) throws IOExcep
             final String name = entry.getName();
             final File current = new File(patchDir, name);
             final String canonicalDestinationPath = current.getCanonicalPath();
-            if (! canonicalDestinationPath.startsWith(patchDir.getCanonicalPath())) {
+            if (! current.getCanonicalFile().toPath().startsWith(patchDir.getCanonicalFile().toPath())) {
                 throw PatchLogger.ROOT_LOGGER.entryOutsideOfPatchDirectory(canonicalDestinationPath);
             }
             if (entry.isDirectory()) {